Method of manufacturing double-curvature sheets



Jan. 27, 1970 e. SABIROV 3,491,569

I METHOD OF MANUFACTURING DOUBLE-CURVATURE SHEETS Filed Sept. 3, 1965 2 Sheets-Sheet 1 G. SABIROV 3,491,569

METHOD OF MANUFACTURING DOUBLE-CURVATURE SHEETS Jan. 27, 1970 2 Sheets-Sheet 2 Filed Sept. 5, 1965 United States Patent 3,491,569 METHOD OF MANUFACTURING DOUBLE- CURVATURE SHEETS Gazi Sabirov, Ul. Sovetskaya 40, Sabirovich Fergana, U.S.S.R. Filed Sept. 3, 1965, Ser. No. 484,838 Int. Cl. B21d 15/00, 1/12 U.S. Cl. 72-468 5 Claims ABSTRACT OF THE DISCLOSURE Sheet bending apparatus in which two rows of rolls are arranged in concentric curved planes in staggered relation, the rolls of one row being convex in shape whereas those of the other row are concave, whereby sheets which are fed between the rolls are deformed to produce sheets with double curvature.

sions along the generatrix: 7 metres in height and 3 metres in width. Production of such sheets requires expensive pressing equipment, heating installations and stamps; moreover, this method involves labour-consuming procedures due to the fact that the heating and swaging of the sheet bar is effected in several steps depending upon the dimensions and thickness thereof.

Apart from this, such method is uneconomic on account of burning and scale losses of metal occurring in production.

It is, therefore, a primary object of the present invention to provide such a method of manufacturing doublecurvature sheets for spherical receptacles that would considerably reduce the amount of labour consumed in the production process involved.

Another object of this invention is to provide such a method of manufacturing double-curvature sheets for spherical receptacles which cuts down the consumption of material.

Another important object of this invention is to provide a method of manufacturing double-curvature sheets for spherical receptacles which enables large-size sheets to be obtained.

With the foregoing and other objects in view, the method proposed in the present invention consists in that sheet bars are shaped on a sheet-bending installati n wherein rolls are arranged concentrically in two rowsin a staggered manner, the rolls of one row being convex in shape whereas those of the other row are concave.

As can be seen from the abovesaid, the method proposed in the present invention makes it possible to produce An embodiment of the present invention is described hereinbelow by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a spherical receptacle composed of sheets manufactured in compliance with the method of the invention;

FIG. 2 is a diagrammatic view illustrating the arrangement of rolls in the sheet-bending installation (side elevation);

FIG. 3 is a diagrammatic view showing the mutual arrangement of a bottom and a top rolls (front elevation);

FIG. 4 shows a sheet bar to be shaped.

A spherical receptacle (FIG. 1) having a diameter of 10,500 mm. and a wall thickness of 22 mm., consists of eighteen double-curvature sheets 1 and two bottom plates 2 also made of double-curvature sheets.

Double-curvature sheets 1, according to the invention, are manufactured by cold shaping on a sheet-bending installation.

In the sheet-bending installation with staggered (FIG. 2) rolls supported at two points, the rolls of bottom row 3 (FIG. 3) are made concave with a radius of curvature R, whereas those of top row 4 are made convex with a radius of curvature R The rows of rolls are arranged concentrically so that the working surfaces of rolls of both bottom and top rows form in the working area (i.e. in the vertical plane) concentrical circumferences with radii R and R the clearance a being provided therebetween. This clearance is adjustable to suit the thickness b (FIG. 2) of sheet bar 5.

It is expedient to have in the abovesaid sheet-bending installation six rolls in bottom row 3 and five rolls in top row 4.

The process of manufacturing double-curvature sheets is as follows.

Sheet bar 5 (FIG. 4) is fed in a cold state into the clearance a (FIG. 3) provided between bottom row 3 and top row 4 of rolls. The bottom row rolls are driven. While rotating, the driven rolls cause sheet bar 5 to move into the working area where said sheet bar is shaped in two mutually perpendicular directions, the shaping in one of the above directions being due to the pressing of the sheet bar by the rolls with concave and convex working surfaces, whereas the shaping in the other direction is due to the concentrical arrangement of the rows of rolls.

Provision should be made in the sheet-bending installation of a means for cooling the rolls during operation; use being preferably made of water as a cooling agent.

The aforementioned method makes it possible to produce double-curvature sheets of great dimensions preferably in length.

What I claim is:

1. Apparatus for bending a sheet of material in double curvature, said apparatus comprising a plurality of rollers in an upper row and a plurality of rollers in a lower row, means supporting the rollers in said rows such that the rows 'of rollers lie in spaced curved planes, the rollers in one of said rows having convex surfaces, the rollers in the other row having concave surfaces, and means for driving the rollers of at least one of said rows in rotation.

2. Apparatus as claimed in claim .1, wherein said convex surfaces are substantia y Parallel to the concave surfaces.

3. Apparatus as claimed in claim 2, wherein each said roller is rotatable about a respective axes, the axes of the rollers in the two rows being staggered.

4. Apparatus as claimed in claim 1, wherein the rollers in the lower row are greater in number than the upper row.

5. Apparatus as claimed in claim 1, wherein said planes in which the rollers lie are concentric thereby defining a space between the rollers which is of substantially constant extent both longitudinally and transversely relative to the rows of rollers.

References Cited UNITED STATES PATENTS MILTON S. MEHR, Primary Examiner US. Cl. X.R. 

